During material handling processes, it is sometimes necessary to employ an apparatus having a clamping arrangement to grasp a load that is to be lifted by an overhead crane. For example, where the load to be lifted is a slab of material, or perhaps a stack of sheets of material, it may be necessary to use a clamping arrangement having fingers or flanges which extend under the load, to grasp or clamp the load in such a manner that it can be safely lifted with a crane.
In some instances, such a clamping arrangement may include moveable clamping arms or legs driven by a motor. Such a motor may be electric, pneumatic or hydraulic.
It is desirable when a motor-driven clamping arrangement is utilized to provide some form of lockout protection for operation of the motor while the load is being lifted. It is desirable that such a lockout arrangement preclude having the clamping arrangement release the load while lifting force is being applied.